Gamer of Ooo
by Captain JN
Summary: A bored and cynical teenager gets run over by a car, only to be reborn as a [Gamer] in the land of Ooo. Sounds easy right? Well, it should be except he attracts [monsters] from every direction in a way he can't control, simply because he's alive and monsters HATE people from other universes. Jared Fields is...the Gamer of Ooo. (SI/OC x Harem. Rated T for cursing.)
1. Chapter 1

_**III**_

 _ **I: Run Over**_

 _ **III**_

Jared Fields was sure he had the most boring life in the entire world. He thought his own life was basically like a soggy bowl of Cheerios, there was no taste but bland before, but now it was painfully taste-less.

His life was monotonous. He sat hours in front of a screen, or a notebook, video games or homework that was pretty much how it worked. Jared often wondered what was the point of doing nothing but stay inside all day. Man was born from nature, why shouldn't he spend most of his time enjoying the wilderness?

Sitting at his desk with his headphones on, he ruffled his light brown hair, staring at his computer game with his light blue eyes, Jared indulged in something every teen did: procrastination.

"Jaaaareeeeddd!" His mom called, "Take out the garbage!"

Groaning, the boy yelled back, "All right!"

Jared pulled the garbage from beneath the sink and his mother handed him a board game, "Can you bring this to Ms. Rodriguez? She let me borrow it."

"Sure whatever mom." Jared took it in his garbage free hand and walked past out the front door to his house.

He used the tips of his fingers on his right hand to lift the garbage lid and throw the trash away in a tiny area next to his house, then he walked across the street but he didn't even see it. The sixteen year old was run right over by a Hyundai Tuscon and killed instantly holding a game of 'Sorry!' he was bringing to his neighbors.

Everything went black.

 _III_

 _III_

Then, his eyes opened and he was laying on his back in a forest, feeling the tiny blades of grass poke his back. He was still wearing the blue jeans and red zip up jacket he had on before but something was glaringly obvious.

He could've sworn he died two damn seconds ago.

Jared stared at his board game freed hand, "What in the fuck…What happened?..."

His attention was brought to the blue box hovering over his chest.

 **The Gamer**

 **Name: Jared Fields**

 **Age: 18**

 **Class: The Gamer**

 **Level: 5  
**

 **HP: 500/500**

 **EP: 400/400**

 **SPECIAL Points: 35**

 **S: 0**

 **P: 0**

 **E: 0**

 **C: 0**

 **I: 0**

 **A: 0**

 **L: 0**

 **Perks: None**

 **Flaws: None**

"Oh, this can't be happening..." Jared covered his face with his hands in disbelief as he laughed.

 **IIIIIIIIIIIIII**

 **IIIIIIIIIIIIII**

 **IIIIIIIIIIIIII**

 _AN: I wondered for a while what the pairing should be…but then I realized that all the ladies in Adventure Time are awesome so…Harem. This is my first story so I'm open to criticism and ideas and things people want to see later. Thanks for reading ciao!_


	2. Chapter 2

_**III**_

 _ **II: Screwed Over**_

 _ **III**_

"Well this couldn't be any shittier." Jared blanked.

 **The Gamer**

 **Name: Jared Fields**

 **Age: 18**

 **Class: The Gamer**

 **Level: 5  
**

 **HP: 500/500**

 **EP: 400/400**

 **SPECIAL Points: 35**

 **S: 0**

 **P: 0**

 **E: 0**

 **C: 0**

 **I: 0**

 **A: 0**

 **L: 0**

 **Perks: None**

 **Flaws: None**

"What so this is like a video game or something?" Jared groaned, looking at the screen. He honestly couldn't be bothered after flipping off death in the face, but since he had nothing else to do but lay there on the forest floor he did it.

The light brown sandy-haired teen reached out and touched the interface, the game blipping in response to his finger.

 **Hello and welcome to the game! To receive an avatar based on your previous life experiences press {here}, to create a new one press {here}.**

Jared was going to go with the first option but a notification popped up.

 **Warning! Your previous characters {Luck} was so low it received death based on system figures. Are you sure you want to go with this option?**

He considered this for a second. His luck did seem terrible, but it was actually pretty decent if that meant he could revive himself in another world right? He pressed the option and the game blipped again.

 **Are you sure you want to choose this option? There will be no way of undoing this choice. ({Yes}/{No})**

He chose {Yes} and the game took a second to register it.

 **Here are your character's stats.**

 **S: 9**

 **P: 32**

 **E: 8**

 **C: 6**

 **I: 43**

 **A: 5**

 **L: 2**

 **Perks:**

 **-Mathematician: +5 to Intelligence when solving math problems.**

 **-Student: +5 to Intelligence when remembering facts.**

 **-Critical Thinker: +20 to Perception and Intelligence when reasoning, solving complex problems or applying knowledge.**

 **Flaws:**

 **-Cynical: -30% Speed in Romantic Route progression.**

 **-Naturally Unlucky: -50% Speed when leveling up or developing any {Skills}**

 **-Bookish: -20% Speed in progressing in {Combat} skills.**

 **-Interdimensional (Set to default due to {Revive}): +200% {Attract} with {monsters} and beings of the Nightosphere.**

"Guess that makes sense," Jared said. Considering his past life it made sense, he mostly stayed inside all day either reading, playing video games or reading. For him to have a body more meant for studying than fighting it would be logical to him.

Plus it wasn't like the world he revived in was full of hot babes and monsters right? Right? Maybe it would've been better to have learned about the world in the first place before choosing his old naturally assigned stats?

His mental question was answered when he heard the strum of a guitar above him. There was a pale and pretty woman wearing suspenders and a red tank top along with very long black hair sitting in a tree branch as she spoke, "You're not from around here are you?"

"Uh, no." Jared trailed, "Who are you?"

"Marceline. And your name is?"

"Jared. Can you tell me how to get back home?"

"Depends on where your home is." Marceline tuned her guitar.

Jared looked around the forest, "Not from around here I think."

Marceline's sharp vampire nose sniffed the air as she hovered towards Jared through the air.

"Uh..." Jared looked at her funny, "How can you fly-"

"You stink of death." Marceline said, "I smelled something weird from my house, but I didn't think it would be this strong."

"Where do you live?"

"In a cave."

Jared snickered, "What're you a vampire? Is that how you can fly?"

"Yeah." Marceline saw the look on his face, "Why, you haven't heard of them?"

"No, I just, thought they weren't real."

"You're strange. And skinny." Marceline saw how weak he looked, "It's no surprise you've died already."

Jared raised an eyebrow, "You can tell just by smelling me?"

"Yup." Marceline placed her guitar that doubled as an axe on her shoulder, "You smell terrible too on the subject. Try not to die twice. Later." she started floating toward the interior of the forest.

"Where are you going?" Jared asked.

"Gotta play at the grove, wanna come with?"

"Nah, I think that." Jared rubbed his chin and his sharp mind went to work, "Since I'm in a new universe there has to be someone who studies interdimensional stuff of some kind. Maybe they can get me back home."

"I don't know anyone like that. But you can talk to Princess Bubblegum. She's really stuck up and kind of annoying, but she knows a lot about everything. She's not good for much, but she is really smart."

Jared took a second to register this, "Princess...Bubblegum?"

"There's a Princess for every kingdom. She's the Princess of the Candy Kingdom."

"Okay how do I get there?" Jared asked.

Marceline leaned her head back, "Ugh! Talk to Fionna and Jake, they know how to get around everywhere."

"How do I get to them?"

"Just leave the forest. But you can't because it's impossible to leave."

"R-Really?"

Marceline's watery laughter rose in the air seeing the frightened look on his face, "I was kidding. The edge of the forest is right there. Fionna lives in a huge tree house in the middle of the hills. Good luck, I think you'll need it."

"Thank you?..." Jared saw her start to hover away and he spoke out to her, "Oh and Marceline? I think you're pretty hot."

"Thanks!" Marceline made him fall back onto his rear when she turned into a fanged monster with red eyes quickly that hissed at him. She laughed again seeing how frightened Jared became, "Wow, you're easy to scare. Bye."

Jared rubbed his back as Marceline left, "She really likes scaring me huh?"

His mind went to work again. If there were people like Marceline in this universe who wouldn't be fazed at all by things like people teleporting from other dimensions, he reasoned that this world would be full of the supernatural to say the least. It was also made pretty obvious to him when the game told him that there were things like monsters and whatever the Nightosphere was.

Jared walked towards the edge of the forest where Marceline pointed and strode out onto the hills she mentioned.

It only took about a half hour of walking for his horrible luck to strike. Jared jumped in surprise and froze in terror when he saw a boned claw rise out of the ground, a horde of skeleton monsters crawling out of the dirt to begin growling at Jared.

"Uh, back off?" he asked helplessly, "Yup, I'm dead." he deadpanned.

He ran up to a skeleton bear with a yell and punched it to no effect in the face, Jared gasping in pain when his fist throbbed in pain when striking its bare skull. The bear growled and slashed Jared across the face, leaving a giant mark across his cheekbone.

Another skeleton monster cut across Jared's arm, tearing up his red jacket in the process and slicing through his body making him tumble back onto the ground.

Jared was already bleeding pretty badly and was really roughed up, and he was never more scared of death in his whole life. He never would've guessed he was going to die twice in the same day.

 **Warning, HP level critical! {54/500 HP}**

Although he would have died again if he hadn't heard a war cry above his head.

A beautiful girl with yellow hair and a silver sword with a light blue core in its hilt appeared and cut away skeleton monsters from Jared.

One of them struck him across the head before she could get to it, and Jared fell over with a large cut on the side of his head, blurry eyed and dazed. The last thing he saw before he passed out was the blonde girl lighting up the tip of her sword with a bright light, using it to pierce through the swath of flames that the firebreathing dragon breathed at her when it reassembled from the horde of defeated skeletons.

That sight of such a heroic young woman defending him from flames as the tip of her sword pierced fire like a stone in a river, her yellow hair flowing about in the direction of the flames as she saved his life, would be something Jared would never forget.

He slipped away not a moment after.

 **IIII**

When he woke up, he started hearing faint voices in the background.

"He's not from our universe Fionna!" a male voice said, "How else can you explain a random human person out in the middle of nowhere?"

"There still could be other humans out there!"

Jared felt like his mouth was drier than ever. He looked over to the windowsill from the couch he was laid on, were those, were those knives falling like rain? He looked at his bandages around his arm and the side of his head, wow he had a headache.

He reached for the pitcher of water on the table and accidentally shattered it when his arm was too weak to pick it up.

The blonde girl who saved him entered with her best friend, who made Jared yelp in surprise when seeing him.

"Never seen a talking dog before?" Jake looked at the teen.

"N-No. Only in cartoons," he said.

"What're cartoons?" the blonde girl asked.

"They're. Wait, they probably don't exist in this universe." Jared stopped himself.

Jake looked up to a defiant Fionna who looked away, "See? I told you!"

"What's your name?" Jared asked the blonde.

"I'm Fionna. This is Jake."

Jake walked up closer to him, "Hi." Jared started rubbing his orange fur, and the dog looked at him funny, "Uh, what're you doing?"

"All dogs are the same." Jared reached out and started scratching Jake's back.

"Well I'd say that ohoho wow!" Jake's back leg started jumping as Jared scratched a certain spot on his back.

"They have dogs where you're from?" Fionna inched closer to him.

"Yeah." Jared stopped scratching Jake's back and extended his hand to his savior, "Jared." he introduced himself.

Fionna looked at his hand, "Um, what is that supposed to mean?"

"It's a handshake? You've never seen one before?"

"I've." she swept a blonde lock behind her ear, "I've never seen another person before."

"What?" Jared's eyes widened, "W-Wait, how old are you?"

"I'm nineteen." she said, "I'm the only human around here."

"Wow, w-what happened?"

"We, we don't know." Jake stated.

Jared looked at her, "Wait, if she's the only human around here, then where are your parents? All people have parents."

"I raised her myself, never met her actual parents." Jake said.

Jared muttered as he rubbed his chin, "Humans don't exist here then? Or maybe they stopped existing."

"What's a handshake?" Fionna wondered.

"You know, you just shake my hand." Jared extended his hand.

Fionna shook his hand slowly, feeling human skin on her hand for the very first time, "Whoa..." she reached out and touched his face.

"Y-Yeah, I'm real Fionna." Jared said as she started feeling around his light brown hair, "No need to do that."

"Wow." Fionna laughed, "I just can't believe it. How did you even get here?"

"I died."

Fionna looked at him, "That is weird."

"You have no idea." Jared looked out at the window, "So, knife storms exist here huh?"

"Yeah they come and go." Fionna said, "Wanna play some BMO while we wait for it to pass?"

"Uh, sure." Jared shrugged, "What's that?"

"BMO!" the talking computer game climbed out of the bookshelf.

"Huh, after everything I've seen so far, I'd say that isn't that surprising."

The two started playing Kompy's Castle on BMO, Jared speaking to him as they progressed, "So computers exist then?"

Fionna looked at him confused and he understood, "BMO had to have come from somewhere. I'm guessing humans have to exist then since I doubt other things are smart enough to make computers like BMO."

"What's a computer?" Fionna questioned.

Jared paused the game and opened his palm, "Can I see it please?"

Fionna placed BMO in his hand and the computer gasped as Jared opened his panel, "Ohp!" it said.

Jared pointed to the circuits inside BMO's mainframe and explained, "These are panels, if I could find the motherboard I could explain better. It's all very complicated and I'm sure you'd have no clue what I said if I explained it, but it takes computing and coding to make something like this. I guess you have other robots like him?"

Fionna took a moment to respond, "We had another one named NEPTR, but we can't find him."

Jared looked around Fionna's tree house, feeling some of his strength come back, "Do you have a basement?"

The trap door that led below creaked open as Jared and Fionna entered it with a ladder, Jared making sure to use his stronger arm that wasn't injured to lower himself down it.

Jared moved aside some trash in the heaps that laid around the cobweb-ridden basement and eventually, NEPTR revealed himself, "It has been 13 months, 2 days, and 8 hours since we have begun our game of Hide and Go Seek, setting a new record. You have won!"

Fionna nodded, "Ohhh, I remember now!"

Jared held NEPTR, the microwave robot chuckling as he held him and examined him, "How did you make this again?"

"He was hit by lightning."

"Hm." Jared put it down and watched NEPTR roll around, "You mind if I stay down here?"

Fionna looked around it, "It's pretty dusty, are you sure you want to use this as your room?"

"It's perfect." Jared pointed to a part of the basement, "My desk could go there. And, oh oh!" He ran to a box filled with green microchips, "This is perfect!"

"But there's nothing but garbage down here." Fionna said.

"Could be more microchips and other things I could use. I don't claim to be a computer expert, but if the first coders could make a system, then so could I maybe."

Fionna rubbed her head, "Ugh, talking to you weirds me out. I can't understand half of what you say. I'm gonna go snack with Jake, I'll bring you back some food and a sleeping bag."

Jared slept there for the night and the hum of knives falling right outside the open garage-type basement let him sleep better. When he woke up he ate the breakfast NEPTR served him that Fionna brought to him the day before and went back to work.

After a few more days of the continuous knife storm outside, Fionna felt compelled to see what this weird interdimensional boy was doing in her basement.

"Hey Jared, just wanted to see how you were doing. What's that thing you're making?"

Jared stopped tinkering on his workbench, "It's a prototype for a Geiger counter, I don't know why but something tells me that if I can measure certain unnatural particles in the air, I can determine if the magic in this world is related to science."

"Wow, you'd get along really well with Bubblegum." Fionna noted.

"I want to see her when the rain storm passes. Since she's the smartest person around I assume, I want to make this thing as a gift for her."

"So what'd you make it out of?"

"Well mostly boron, it's reactive to other particles like alphas, neutrons, and lithium ions which help. Now all I gotta do is make a computer system to measure this electronically."

Fionna held the prototype in her hands, "So you're like a brainiac super genius type right?"

"Not really. I messed around a lot with Geiger counters and computers for my senior project before I graduated a month ago."

"Senior project?"

Jared raised an eyebrow, "You know, for school. It's-nevermind." Fionna watched him continue to tinker, before he accidentally hit an electrical spark and cursed, "Fuck!"

"What's that word mean?" Fionna asked.

"You don't wanna know. Pretend I never said it." Jared refused to teach her it, already accustomed to her innocent naivety.

"What's your world like?" Fionna passed her hand over the diagrams Jared drew of his Geiger counter.

Jared took the screwdriver NEPTR passed him to continue working on it, "Pretty boring. Very different from this one, no monsters or vampires or anything like that."

"Is that why you've never had to fight?" Fionna noted his skinny physique.

"More or less." Jared leaned back in the chair Fionna lent him.

"I've been fighting monsters my whole life." Fionna said, "Maybe I could teach you how to swing a sword?"

Jared shook his head, "As useful as that would be to learn, I can't, because, you know." He pointed to his bandages from the monster attack.

"Yeah. Oh, maybe you could teach me all that science biz." she leaned on his desk.

Jared looked her up and down, "You'd be bored instantly, even if I taught you the basics."

"I can read."

"Can you add and subtract?"

She nodded.

"Well what about factoring? Or multiplication?"

"Uh..."

Jared pointed at her, "All that's really boring. Especially for someone like you."

Red rose in Fionna's cheeks, "What's that supposed to mean?"

"Odds are you've never developed the ability to sit down and learn because you've been dealing with combat your whole life. Like card games or board games, that stuff bores you right?"

Fionna remembered her trying to play Card Wars with Jake, "I mean," she held her arm, "Yeah."

"There you go, you won't be able to stand it." Jared shrugged.

"Well, at least I'm not boring, staying shut inside here all day." Fionna crossed her arms.

Jared stayed silent as the rainfall of knives made his point, tinkering again.

"You know what I mean Jared!"

He looked up at Fionna, "I'm a bit surprised really. I thought you'd be nicer to me considering our situation."

"What situation!?" Fionna snapped at his cynicism.

"Like, repopulating the planet. Sex and all that?"

"What's...sex?"

Jared tapped himself on the head, making sure not to hit his bandages as he spoke condescendingly, "See, I forgot you've never been to school. Let me put it to you like this, humans don't come from a doorstep or whatever Jake must've told you. They come from each other, only humans can make other humans. How they make them, is called sex."

"And how do they-"

"I'm not telling you Fionna." Jared blanked in his usual dry and cynical tone.

"What're you saying? That I'm not sex-able!?" Fionna balled her fists, not really knowing why she was feeling embarrassed at what she thought he implied.

Jared couldn't help but laugh, "I think I should give you a lesson in how to talk first."

Fionna slapped him after seeing him laugh so much at her lack of schooling, the boy gasping in pain when he landed on his injured arm as the strike hit him out of his chair.

"Oh I'm so sorry!" she ran to his side, "I didn't mean to-"

"It's fine." Jared laughed as she helped him up back into his chair, "Probably should've remembered you can't interact with people yet first."

She slammed him into his chair in anger as she climbed out of the basement, hearing him chuckle again and speak out to her, "Tell Jake I want to try some of those games!"

Jake watched as Fionna was washing dishes angrily, "So, how is he?"

"He's an idiot." Fionna slammed a dish into the sink, "I just, I just think he's so annoying. He's like Bubblegum but disrespectful. He wants to play Card Wards with you."

Jake glared at the entrance to the basement in anger, "Will do."

He never would've guessed a human boy of 18 from another dimension would be much better than he was at Card Wars. After easily understanding the rules, Jared schooled Jake after a few short rounds.

"I play Slimeball Horror." Jared dropped his creature attack and shredded Jake's board, "You have no draw stance this late in the game or any creatures to block. That's the game."

Jake slammed his cards down, Jared growing in fear as he grew to a massive proportion and shoved his gigantic finger in his face, "That was beginner's luck through and through!"

"S-Sorry!" he stuttered, knowing Jake had the strength and size to crush him into a pancake easily.

Jake shrunk back down and left with mutters, "Stupid. Magic. Random. Other world. Stupid."

Jared tinkered for a few minutes before feeling guilt wash his stomach. He climbed back into the tree house with his good arm and found Fionna washing dishes in the kitchen.

"Hey."

Fionna put a dish away.

"I'm sorry for saying all that. I just never was in a position like that before."

"I bet I couldn't blame all the girls from your world couldn't I?" Fionna raised a yellow eyebrow angrily before putting another dish away.

"Not really." Jared held her arm, making her look at him as he looked into her eyes, "Fionna. You are sex-able, even though, hot's the better word."

Fionna shoved him back a little as she shook her white bunny hooded head, "Idiot."

Jared sighed, "Fionna, I am sorry. I've never had to say this before but, thanks for saving my life. Until recently, it didn't seem to be all that exciting anyway. Until I came here. I'll never forget that I wouldn't be alive without you."

Fionna turned around as Jared walked away, "Hey." He turned back around, "When your arm gets better, I'll teach you how to swing a sword."

"Do you have another one for me?"

Fionna snickered and swept a yellow strand of hair behind her ear as she leaned on the counter, "I have more than enough I'm sure."

Jared nodded and walked back to the basement, Jake striding in smugly, "So, he's not so stupid now eh?"

Fionna shook her head as knives pattered against the ground outside acting as rain, "Sh-Shut up." she blushed.

At that very moment, Jared received a notification.

 **You have received +Affection with Heroine Fionna. Welcome to the romantic routes gamer!**

He raised an eyebrow at this. The hell? Well, at least this was new.


End file.
